package com.lhx.linked;

public class ReverseList02 {
    static class ListNode{
        int val;
        ListNode next;

        public ListNode(int val, ListNode next) {
            this.val = val;
            this.next = next;
        }
    }

    //迭代
    public static ListNode iterate(ListNode head) {
        ListNode prev = null,next;
        ListNode curr = head;

        while(curr != null) {
            next = curr.next;
            curr.next = prev;
            prev = curr;
            curr = next;
        }
        return prev;
    }

    public static void main(String[] args) {
        ListNode node5 = new ListNode(5,null);
        ListNode node4 = new ListNode(4,node5);
        ListNode node3 = new ListNode(3,node4);
        ListNode node2 = new ListNode(2,node3);
        ListNode head = new ListNode(1,node2);

        ListNode prev = iterate(head);
        ListNode pre = prev;
        while(pre != null) {
            System.out.print(pre.val);
            pre = pre.next;
        }
        System.out.println(pre);
    }

}
